1. Field of the Invention
The present invention relates to printing machines, and more particular, to silk screen printing machines capable of printing on a variety of geometric configurations.
2. Prior Art
Silk screening is of course an ancient art, but it has been modernized to significant extents as a result of automation or semi-automation of the equipment utilized to produce the silk screening designs. One of the major commercial applications today is in the printing of bottles and plastic containers of various geometric configurations and surfaces of revolution such as for example, cylindrical, oval and rectangular.
In some operations of printing such geometrically configured containers and the like, it is necessary to hold the silk screen stationary while moving the squeegee across the surface of the silk screen in order to pass the printing liquid through the screen and create the design. In still other applications it is necessary to reciprocate laterally the silk screen while maintaining the squeegee stationary in engagement with the surface of the screen in order to pass the printing liquid through the screen.
Since silk screen printing machinery is often utilized for a variety of applications it must generally be adaptable to either mode of operation. The present invention, however, is more closely relatd to those silk screen printing apparatus when used in such a manner that the silk screen is reciprocated laterally. When the silk screen machine is set up in this manner, i.e. to reciprocate the silk screen laterally while holding the squeegee stationary, it is generally used on objects which possess surfaces of revolution that are to be printed on, such as cylindrical containers. The container is positioned beneath the squeegee so that the surface rotates parallel to and in tangential contact with the squeegee as the silk screen with the printing liquid is passed therebetween. Many such existing machines are capable of only printing on such containers which have a relatively small diameter. This is true even though there is additional room for laterally reciprocable movement of the silk screen carrier within the frame structure of the printing apparatus, since in many such apparatus there is an interference with the further outward movement of the silk screen carrier, with other parts of the machine. Thus, such machines cannot be utilized to their fullest to accomodate larger diameter containers or to print over a greater extent of surface area on a container because of this limited movement.